x86/amd-iommu: Use only per-device dma_ops
Unfortunatly there are systems where the AMD IOMMU does not
cover all devices. This breaks with the current driver as it
initializes the global dma_ops variable. This patch limits
the AMD IOMMU to the devices listed in the IVRS table fixing
DMA for devices not covered by the IOMMU.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index cd8cbeb..b2c309b 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -30,6 +30,7 @@
#include <asm/proto.h>
#include <asm/iommu.h>
#include <asm/gart.h>
+#include <asm/dma.h>
#include <asm/amd_iommu_proto.h>
#include <asm/amd_iommu_types.h>
#include <asm/amd_iommu.h>
@@ -2383,6 +2384,23 @@
.dma_supported = amd_iommu_dma_supported,
};
+static unsigned device_dma_ops_init(void)
+{
+ struct pci_dev *pdev = NULL;
+ unsigned unhandled = 0;
+
+ for_each_pci_dev(pdev) {
+ if (!check_device(&pdev->dev)) {
+ unhandled += 1;
+ continue;
+ }
+
+ pdev->dev.archdata.dma_ops = &amd_iommu_dma_ops;
+ }
+
+ return unhandled;
+}
+
/*
* The function which clues the AMD IOMMU driver into dma_ops.
*/
@@ -2395,7 +2413,7 @@
int __init amd_iommu_init_dma_ops(void)
{
struct amd_iommu *iommu;
- int ret;
+ int ret, unhandled;
/*
* first allocate a default protection domain for every IOMMU we
@@ -2421,7 +2439,11 @@
swiotlb = 0;
/* Make the driver finally visible to the drivers */
- dma_ops = &amd_iommu_dma_ops;
+ unhandled = device_dma_ops_init();
+ if (unhandled && max_pfn > MAX_DMA32_PFN) {
+ /* There are unhandled devices - initialize swiotlb for them */
+ swiotlb = 1;
+ }
amd_iommu_stats_init();